His rallies set pulses racing, with people leaving both exhilarated and terrified

From loyalist rabble-rouser in the Sixties, to the IRA's 'greatest-ever recruiting sergeant' in the Seventies, to sharing government with Sinn Fein in the Noughties, David McKittrick charts Ian Paisley's incredible transformation

The two boys both followed in their father's footsteps: Ian is today an MP in the party he set up, while Kyle is a minister in the Church he founded.

Paisley had other followers back then in the 1960s, but they tended to be confined to traditional hardline working-class areas such as the Shankill.

It was not exactly a golden age, but it was a time of lessening tensions and an improving political and social atmosphere, with talk of better Protestant-Catholic relations.

Ian Paisley opposed all this every step of the way, in the most dramatic and uncompromising terms. His speeches potently combined politics and religion, warning against any idea of concessions to the twin foes of nationalism and Catholicism.

He took no prisoners in his rhetoric, seamlessly combining attacks on republicans with attacks on the Catholic Church. He once declared, for example, "Are we going to agree to a partnership with the IRA men of blood who have slain our loved ones, destroyed our country, burned our churches, tortured our people and now demand we become slaves in a country fit only for nuns' men and monks' women?"

He dismissed allegations that he was making a bad situation worse with his trademark guffaws and counter-attacks, brushing aside allegations that his intemperate style could have cost lives and made reconciliation much more difficult to achieve.

To accusations that he fostered disharmony and helped keep the two communities apart, he cheerfully entered a plea of guilty. During one sermon he summed up his philosophy: "If you compromise, God will curse you."

His rallies sent pulses racing: many of the people streaming away from them had faces shining with excitement, his demagoguery having exhilarated and terrified them with his dire warnings that the IRA and Rome were both out to get them. A senior English clergyman once described his fire-and brimstone histrionics as religious cabaret.

The Catholic Church was stronger then, but there wasn't much of an IRA. Looking back, many have wondered whether the Paisley rhetoric helped create the conditions for its growth into such a fearsome terrorist organisation.

Certainly, Gerry Adams of Sinn Fein has written that one of his earliest political experiences was observing a riot which followed some Paisley bombast. Adams wrote of "rallies at which Paisley bellowed forth a message of virulent religious hatred".

In those early days, the preacher was regarded as being beyond polite society, well beyond the pale: the middle class scoffed at him as a variant of Vincent Price playing Dracula.

While his conduct thrilled his Protestant faithful, it had a very different effect on many nationalists. A Protestant minister, the Rev William Arlow, once confided he had asked IRA leader Daithi O Conaill about a rumour the IRA might try to kill Paisley.

He recalled: "O Conaill just simply told me, 'There's no way we would kill Ian Paisley. Paisley is the best recruiting sergeant we've got.'"

The clergyman related O Conaill saying: "When they hear him, a chill goes down the spine of every Catholic in west Belfast. And after that we have no trouble getting volunteers, safe houses and money.'"

It was an extraordinary career, encompassing the pulpit, marches and rallies and two brief spells in jail, a career packed with incident and drama, with a thousand demonstrations, diatribes and walkouts.

He was a major cause of the breakup of the one-time monolith of the Ulster Unionist party, which had until the 1960s successfully acted as a broad church for almost all strands of Protestants and unionists.

When Paisley first launched his attacks on that party, it was routinely described as a monolith. By the time of his death, he had helped reduce it to a shambles.

Terence O'Neill, unionist prime minister in the 1960s, struggled to refute his accusations that unionism was going soft. At first derided as a pantomime demon, Paisley's success at the ballot-box demonstrated that he had political as well as rhetorical clout.

Other troublesome figures had been bought off by being brought inside the fold. But since Paisley was not interested in joining any team, there was no real way for O'Neill or anyone else to silence his disruptive dissent.

He staged an almost ceaseless series of demonstrations, among them a protest against the lowering of the flag on Belfast City Hall to mark the death of Pope John XXIII. He led a thousand supporters in a protest against "the lying eulogies now being paid to the Roman anti-Christ".

His flair for articulating – and amplifying – the deepest fears of many Protestants meant he harvested votes in large numbers. He formed first the Protestant Unionist party and later the Democratic Unionist Party, which was to constitute a force in unionist politics throughout the Troubles.

While Paisley was perversely useful to the IRA, he was absolutely loathed by all those who over the years pursued the idea of an agreed settlement.

A score or more of Northern Ireland secretaries came and went from Belfast, some of them trying hard to find an accommodation. The local centrist parties all favoured some form of power-sharing, but they and British ministers were repeatedly thwarted by the twin obstacles of Paisley and the IRA.

James Callaghan accused him of "using the language of war cast in a biblical mould", while Edward Heath called him a demagogue and a wrecker. Reginald Maudling found him "one of the most difficult characters anyone could hope to deal with", while William Whitelaw marvelled at his ability to destroy and obstruct, his "unrivalled skill at undermining the plans of others".

Roy Mason remembered him as "an oafish bully, a wild rabblerouser, a poisonous bigot." James Prior thought him "basically a man who thrives on the violent scene. His aim is to stir the emotions of the Protestant people. His bigotry easily boils over into bombast."

Douglas Hurd wrote: "The negative element in his character lay at the centre and drove forward his extraordinary energy. There was nothing positive in his beliefs. He was never a man with whom a minister could do serious business."

Even John Major, normally slow to criticise, described him as mischievous, histrionic, and "hell-bent on destroying" his peace efforts.

His mood swings, always unpredictable, led former civil servant Maurice Hayes to give this thumbnail sketch of his larger-than-life character:

"He is a complex personality. I have often thought there are about six Paisleys. Two of them are very nice people, two quite awful and the other two could go either way.

"He worked unceasingly for all his constituents, regardless of religion. True, he could be, and was, a rabblerouser. He very often filled the atmosphere with an inflammable vapour that other people could and did ignite. In public he often appeared a driven man. In private he could be affable and very amusing."

His own verdict on British politicians was equally damning: "When I consider the drunkenness, lewdness, immorality and filthy language of many MPs, I care absolutely nothing for their opinions. Ulster Protestants are not interested in gaining the goodwill of such reprobates."

Violence – from loyalists as well as republicans – poisoned the atmosphere and so did Paisley's absolute insistence that no deal could be done with nationalists, Catholics and above all republicans.

In effect, he exercised a veto on compromise, helping build a reputation for Northern Ireland as a place of endless violence and perpetual disagreement.

The first cryptic signs that something might change came from the republican and nationalist side, where the rhetoric changed although the bombing continued. Paisley watched this with keen interest, but for years gave no indication that he might be prepared to move.

But his position became steadily stronger as he gradually overtook the main Ulster Unionist party, establishing itself as the strongest Protestant voice.

At this point, a new approach became theoretically possible, since his new strength meant that his would not just be one face among four or five in any new administration, but the leader of the pack.

Still, his years of implacable negativity made it seem impossible that he would do a deal, especially since the numbers meant he would be going into government with Sinn Fein.

This was the party he had vowed to destroy, with election posters featuring himself wielding a large sledgehammer over the slogan "Smash Sinn Fein".

The very idea of a Paisley-Sinn Fein government was, therefore, unthinkable – until the very moment when cameras were allowed into a Stormont committee room to show Paisley and Gerry Adams, the ancient foes, sitting at the same table.

Everyone gaped in amazement as they announced they had reached agreement on forming a power-sharing government, headed by their two parties and including others.

Paisley would be First Minister, with Martin McGuinness of Sinn Fein – an acknowledged former member of the IRA – as his deputy.

The astonishment grew as the two old warriors of the Troubles developed not just a working relationship, but an actual genuine friendship.

In the couple of years that followed, a completely new Paisley emerged: a leader readily prepared to let bygones be bygones and leave the past behind.

As First Minister, he did not bother much with actual administration, instead embarking on a sort of lap of honour, taking in places which had always disapproved of his previous record.

He was feted in Dublin and Washington and elsewhere, no longer the man who gloried in conflict, but instead, suddenly, an internationally acknowledged peacemaker.

My grandmother would have been stunned at his remarkable journey.

How orator flagged up his presence

The year 1964 was when Ian Paisley forced himself into the public consciousness and marked himself out a unionist leader of the future.

During that year’s general election campaign, a republican candiate displayed a tricolour from the window of his office at Divis Street in west Belfast.

Paisley threatened that, if the RUC did not remove the flag, he and his supporters would march on the office and take it down themselves.

(The Flags and Emblems Act banned the public display of any symbol with the exception of the Union flag that could cause a breach of the peace.)

In response to Paisley’s ultimatum, RUC officers arrived at the building, smashed their way inside and seized the tricolour, leading to prolonged rioting in nationalist areas. Thirty people, including at least 18 police officers, had to be hospitalised.

The “Tricolor riots”, as they became known, were the worst in Belfast since the 1930s.

Gerry Adams, then a young man, remembers the incident as having a defining influence on his political development.

“The Divis Street event set the template for much of Paisley’s subsequent political career,” the Sinn Fein president recalled. “It also had the additional effect of encouraging me to become politically curious and then active.

“I went off and got a copy of the notorious Special Powers Act. I read it and other material and began to learn about the causes of discrimination and sectarianism. I started folding election leaflets for the republicans.”